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000
FXUS66 KSEW 061036
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
336 AM PDT Tue Jun 6 2023

.SYNOPSIS...Dry conditions, unseasonably warm temperatures, and
elevated fire conditions will persist across much of western
Washington into Thursday. Upper level troughing then looks to
become the dominant influence again later in the week for cooler
temperatures and increased shower chances.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...High pressure brings warm
and dry conditions to western WA over the next few days,
especially in the interior and Cascades. In the interior, highs
will reach the 70s to mid 80s today with mid to upper 80s on
Wednesday. The Heat Risk is Moderate but we will see some relief
from the heat with overnight lows in the 50s. Expect cooler
conditions along the coast with NW flow (highs in the 60s and
70s). Fire weather concerns remain elevated across the region
with the lack of rain, drying fuels and warm/dry/unstable
conditions, thus prompting an early season Red Flag Warning for
the west slopes of the Cascades.

The ridge slides east on Thursday and an onshore push will bring
some clouds and cooling conditions. However, afternoon highs will
still trend above normal with temps in the interior reaching the
mid to upper 70s. There`s a slight chance of showers in the
Cascades with an increase in mid-level moisture and instability.
Cannot rule out isolated thunderstorms near the crest. 33

.LONG TERM /FRIDAY THROUGH MONDAY/...A trough over the West may
bring more moisture and showers to the Cascades on Friday and
Saturday. A few showers may drift over the lowlands on Friday but
total rainfall amounts will be low (only a few hundredths if
anything per ensemble guidance). A weak ridge brings slightly
warmer conditions early next week with temps in the 70s to lower
80s again. The coast will remain cooler and in the 60s with NW
flow. 33

&&

.AVIATION...Quiet and stable conditions continue with west-southwest
flow aloft today. Flow aloft weakens tonight into Wednesday morning
as a weak ridge moves overhead around an upper low over northern
California. VFR conditions at the terminals through the TAF period
with breezy to perhaps gusty north-northwest winds, especially at
the Puget Sound terminals from 10 to 15 kt and occasional gusts to
20 kt possible.

KSEA...VFR conditions today with breezy northwest winds from 10 to
15 kt. Wind gusts should be much less than yesterday, though
occasional gusts to 20 kt cannot be entirely ruled out. Winds turn
lighter at 5 kt or less after 03Z this evening. The airmass will be
stable.

Davis

&&

.MARINE...With high pressure located well offshore and a thermally-
induced surface low over northern California and associated trough
extending northward into eastern Oregon and Washington, we will see
continued northwesterly flow, though weaker than the past few days.
Small Craft Advisories continue for the offshore waters with gusts
from 20 to 25 kt today. Winds should trend lighter and mostly below
21 kt over the inner coastal waters, though localized occasional
advisory-level gusts cannot be entirely ruled out. Rough and choppy
seas are to continue today, especially for the offshore waters
thanks to the short-period primary wave group. A secondary and
longer period wave group from the southwest will likely become
dominate at times today, though wave heights are lower with this
group-mostly 2 ft or less. Remaining Small Craft Advisories for the
offshore waters will expire at 11 PM this evening as winds subside.

Continued northwesterly winds down the Strait of Georgia will
continue the Small Craft Advisory for the Northern Inland Waters
through 11 AM this morning, though greatest likelihood for advisory-
level winds gusts will be north of the San Juan Islands.

Northwesterly, onshore flow continues into Wednesday, though weaker
as the surface offshore weakens and shifts slightly southward away
from our waters.

Mostly quieter conditions Thursday and Thursday night, though Small
Craft Advisories will likely be needed for the central and eastern
Strait of Juan de Fuca with a long-duration push. Northwesterly flow
looks to pick back up as the high shifts northward by Friday into
this weekend with additional Small Craft Advisories being possible.

Davis

&&

.FIRE WEATHER...The combination of dry fuels, low RH (daytime
relative humidity in the teens and 20s) and unstable conditions
(mid-Haines 6) leads to an early season Red Flag Warning for the
west slopes of the Cascades today. Fire weather concerns remain
elevated in the central/southern interior with warm and dry
conditions too even though winds will be a little lighter compared
to Sunday and Monday. The air mass remains unstable on Wednesday
however RHs will be a little higher with the flow becoming more
westerly. May see isolated showers and thunderstorms on Thursday
and Friday in the Cascades although highest confidence is east of
the crest. 33

&&

.HYDROLOGY...The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated as needed.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning from 10 AM this morning to 10 PM PDT this
     evening for West Slopes of the Central Cascades Generally
     above 1500 Feet-West Slopes of the North Cascades Generally
     above 1500 Feet.

PZ...Small Craft Advisory until 11 AM PDT this morning for Northern
     Inland Waters Including The San Juan Islands.

     Small Craft Advisory until 11 PM PDT this evening for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

&&

$$